The Ontario legislature voted in favor of a low enabling the use of Passport Cards and enhanced driver licenses to cross the U.S./Canada border. But the law is not without its share of controversy, according to a news report from The Toronto Star.

The new travel documents are an alternative to the traditional passport books. The documents are called for under the U.S. Western Hemisphere Travel Initiative, which require additional identification at land borders. The new documents are voluntary.

Opponents say the information on the cards could be duplicated or it could be used to track travelers. The cards use long-range radio frequency identification technology that can be read from up to 15 feet away. The cards do not contain any biographical information, just a number that is used to reference information stored in a secure database.

But Canadian privacy advocates are still concerned. A group, including the Canadian Civil Liberties Association, say the danger is so great the slogan on the province’s vehicle license plates should be changed to “Ontario: You’ll be Discovered.”